#
Volume test (Roberts 63)

for wireframe images - "the hidden-line problem"
assumes an infinite eye point (0, 0, -inf)

2-D:Test all edges against all polygons

3-D: Test all edges against all polyhedra

Define polygons/polyhedra as the intersection of positive halfspaces
of planes

hold t constant and it defines a ray

if that ray is in the negative halfspace of any of the planes, that
point is visible

**time**: O(n^{2}), where n = # edges

**preprocessing**: none

**coherence**: takes advantage of edge coherence

**scene footprint**: total

**memory footprint**: a polygon and an edge

**overdraw**: worst possible case! Every edge is checked regardless
of its location

**clipping**: not done

**transparent objects**: could be extended to do it

**use**: no one in their right mind uses this.